1. Field of the Invention
The present invention relates to a miniature fan and, more particularly, to a blower-type miniature fan that outputs air from a lateral side thereof.
2. Description of the Related Art
FIGS. 1 and 2 show a typical conventional blower-type fan 9 including a base 91 in the form of a hollow housing having an air outlet 911 in a lateral side thereof and an opening 912 in a top side thereof. A stator 92 is mounted in base 91. A rotor 93 includes a hub 931 rotatably received in base 91. A metal ring 932 is coupled to an inner periphery of hub 931, and a permanent magnet 933 is coupled to an inner periphery of metal ring 932, so that metal ring 932 is located between hub 931 and permanent magnet 933 to provide a magnetically sealing effect. An annular plate 934 extends radially outward from and is integrally formed with an outer periphery of hub 931. A plurality of blades 935 are mounted on a top face of annular plate 934 and spaced from one another at regular intervals. A cover 94 is mounted on top of base 91 and includes an air inlet 941 aligned with opening 912 of base 91.
In use, flux linkage between stator 92 and permanent magnet 933 causes rotation of rotor 93 to draw airflow into fan 9 from air inlet 941. Airflow drawn into fan 9 accumulates between cover 94 and base 91 and is then driven by rotor 93 to the environment via air outlet 911 to provide a heat-dissipating effect. However, the outer diameter D of hub 931 of fan 9 must be large enough to receive metal ring 932 and permanent magnet 933 that are both mounted inside hub 931. As a result, the overall size of fan 9 can not be effectively minimized; namely, miniaturization of fan 9 is not easy.